Abstract

Two hundred-sixteen Angus and Angus-cross steer calves (690 lb) were used in a 129- day finishing study to evaluate different implant strategies, including an experimental new implant for feedlot cattle that contains 28 mg of estradiol benzoate and 200 mg of trenbolone acetate (EBTBA). Treatments were 1) nonimplanted control, 2) implanted and reimplanted with Synovex-Sfi, 3) single initial implant with EBTBA, 4) single initial implant with Revalor-Sfi, 5) implanted with Synovex-S and reimplanted with EBTBA, and 6) implanted and reimplanted with EBTBA. Initial implants and reimplants were administered on day 0 and 63, respectively. All implant treatments increased feed intake, slaughter and carcass weights, and rate and efficiency of gain. Compared with other implant treatments, the use of EBTBA as a reimplant treatment (trts 5 and 6) resulted in improved (P